Anyways, I think Ethelberth's regional results are wrong.
Or maybe he used a different system for allocating seats (not D'Hondt) or gave the constituencies different totals (because each province except Ceuta and Melilla is guaranteed three seats, Castile is grossly overrepresented.)
I have
PSOE 157
PP 145
IU 11
CC 4
BNG 3
PA (Andalusian regionalist, not in the current parliament) 2
All others unchanged.
Back to "Castile overrepresented": On a uniform 2% swing from PSOE to PP, PSOE would still lead in the popular vote 40,7%-39,7%, but PP would be the strongest party 157-155 (with the Esquerra losing one and the IU gaining one)
I think you are closer
my calculation (D'hondt) are like yours but 156 for PSOE, 12 for IU